The present invention relates to a method of measuring movement of solid particles and particle interactions in a flowing system. In particular, the invention relates to radioactive particle tracking within a chemical reactor.
The introduction of new computational fluid dynamics (xe2x80x9cCFDxe2x80x9d) models describing flow phenomena in chemical reactors offers information including voidage maps, pressure distribution maps and particle velocity maps as a function of position and time and in two or three dimensions. Such models can be used for predicting hydrodynamics in the reactor. However, there is very little direct verification of all these maps, making the applicability of such models dubious. One way to validate such models is to perform simulations using laboratory or pilot plant scale reactors equipped with a variety of sensors that can measure reactor properties. These properties usually include local pressure and temperature measurements, superficial fluid flow rate measurements and localized measurements of bubble imaging through intrusive probes.
It would be advantageous to possess techniques to measure reactor properties without intrusive probes to provide multi-dimensional information of properties similar to those predicted by computational fluid dynamics and to verify those predictions. Such techniques may then be used to calibrate CFD models and apply them as tools for scale-up predictions.
The present invention provides for methods of measuring movement of solid particles and particle interactions in a three-dimensional flowing system. Such methods are useful for predicting and verifying the hydrodynamic behaviour of flowing systems which allows one skilled in the art to design or modify flowing systems to enhance their efficiency or to suit a particular purpose.
In one aspect of the invention, said method comprises the steps of:
(a) providing at least one radioactive tagged particle within the flowing system;
(b) providing at least one image receptor capable of detecting the position of the tagged particle in the x-z plane; and
(c) periodically recording the position of the tagged particle in the x-z plane over a length of time.
In a preferred embodiment, the method further comprises the steps of providing a second image receptor capable of detecting the position of the tagged particle in the y-z plane and periodically recording the position of the tagged particle in the y-z plane at the same times the first image receptor records the position of the tagged particle in the x-z plane. The first and second image receptors may be gamma cameras and the particle may be tagged with radioactive technetium.